State Of Texas Wrongful Death Laws

Wrongful Death! My mother lost her life to what seems to be an incorrect reading from an EKG machine.?
My mother went to the doctor one morning complaining of chest pain that she had had for several days. The doctor did an EKG on her and it came back abnormal. The doctor sent her back to work and she died about three hours later. I have spoken to a few law firms and they will not take the case because the doctor does not carry an umbrella insurance. Apparently he does not have admitting rights for the hospital so he does not have to carry a certain type of insurance. Help? State of Texas by the way. Also, I find out a few months later that he buys a new EKG machine. Can anyone help please. I understand that I only have 2 years to do anything about this.
Wow! I have received five answers so far and I really appreciate every one of them. Thank each of you for your support in telling me that you are sorry for my loss. It means alot. really. As for choosing the best, I am just not sure. I think each of you had great input so I will have to sleep on it. Thank you again
Do you have proof that the results came back abnormal? If that is true, she should have been informed and at least told to go to a hospital or sent there automatically. I do not understand why the doctor would need a new machine, though, if as you say, the first machine showed an abnormality in her EKG. Now, since I had heart trouble recently and had to have open heart surgery, I happen to know that an EKG does not always show heart problems. My EKG, a week before my surgery read normal. Only further tests identified the problems and they were done several days after the EKG.